JP6545170B2 - Position determination system - Google Patents

Description

  The present invention relates to a position determination system, method and computer program for determining the position of a catheter located in an object in an image of the object during an interventional procedure. The invention further relates to a positioning system that identifies the position of the catheter in the subject during the interventional procedure and a calibration method that calibrates the position determination system.

  Conventional catheter ablation procedures in electrophysiology (EP; ElectroPhysiology) can be guided by x-ray fluoroscopy that is often supplemented by an electromagnetic tracking (EMT; ElectroMagnetic Tracking) system for tracking the catheter. A x-ray fluoroscopy system is used for x-ray fluoroscopy guidance. The x-ray fluoroscopy system acquires x-ray projection images during a catheter ablation procedure. The x-ray projection images are preoperative 3 such as computed tomography (CT) or magnetic resonance (MR) images to provide three-dimensional anatomical information during catheter ablation procedures. It can be registered with dimensional images. In particular, the position of the catheter tracked by the EMT system may be shown in the pre-operative three-dimensional image to indicate the position of the catheter relative to the patient's internal three-dimensional anatomy. However, acquiring an x-ray projection image results in a relatively high radiation dose being applied to the patient.

  The object of the present invention is a position determination system, method and computer program for determining the position of a catheter located in an object in an image of the object during an interventional procedure, comprising: It is an object of the present invention to provide a position determination system, method and computer program that enables reduction, in particular the complete avoidance of x-rays. A further object of the present invention is to provide a positioning system for identifying the position of the catheter in the subject during the interventional procedure and a calibration method for calibrating the position determination system.

In a first aspect of the invention, there is provided a position determination system for determining the position of a catheter located within an object in an image of the object during an interventional procedure. The position determination system is
An imaging device for generating an image of the object before the intervention procedure is performed at an imaging site;
An imaging-time optical marker generation device that generates an optical marker at a position on the surface of the object before the intervention procedure is performed at the imaging site;
A positioning device for determining the position of the catheter during the interventional procedure at the intervention site;
An interventional light marker generation device for generating a light marker at the location on the surface of the object at the intervention site;
A spatial relationship providing unit for providing an imaging spatial relationship between the imaging device and the imaging light marker generation device and an intervention spatial relationship between the positioning device and the intervention light marker generation device;
And a position determining unit for determining the position of the catheter in the generated image based on the position of the catheter determined by the positioning device and the imaging spatial relationship and the intervention spatial relationship.

  An imaging spatial relationship between the imaging device and the imaging light marker generating device, an intervention spatial relationship between the positioning device and the interventional light marker generating device, and at the same position on the surface of the object Due to the generation of light markers by the light marker generation device at the time of imaging and the light marker generation device at the time of intervention, the position of the catheter in the generated image can be accurately determined without necessarily applying x-rays to the object.

  The imaging site is a place where imaging by the imaging device and generation of an optical marker by the optical marker generation device are performed at the time of imaging. For example, the imaging site may be an imaging room in which the imaging device and the light marker generation device at the time of imaging are located. The intervention site is where the intervention procedure takes place. For example, it may be an operating room with the positioning device and the interventional light marker generating device.

  The imaging device is preferentially configured to generate a three-dimensional image of the object, such as a computed tomography image and / or a magnetic resonance image. The positioning device is configured to determine the position of the catheter preferentially by using EMT and / or Optical Shape Sensing Tracking (OSST) techniques. The imaging light marker generation device and the interventional light marker generation device preferentially comprise several light sources, in particular lasers, which generate light markers at positions on the surface. Preferentially, the imaging-time optical marker generation device and the intervention-time optical marker generation device are configured to generate three or more optical markers at three or more positions on the surface. If a laser is used, an optical marker can be generated very accurately by the coherence properties of the laser light, which further increases the accuracy of determining the position of the catheter in the generated image.

  The imaging-time optical marker generation device has a light source emitting light according to a first ray geometry to preferentially generate an optical marker, and the interventional light marker-generating device preferentially generates an optical marker To emit light according to a second beam geometry, said first beam geometry and said second beam geometry being preferentially the same. The spatial relationship donor unit is preferentially a storage unit in which the spatial relationship is pre-stored, from which the spatial relationship can be read out to provide them. The stored spatial relationships may be predetermined during the calibration procedure.

  The imaging light marker generation device and the imaging device may be separate devices, or they may form an integrated device. In the latter case, the imaging light marker generation device may have a light source associated with the imaging device. Also, the interventional optical marker generation device and the positioning device may be separate devices, or they may form an integrated device. In the latter case, the interventional light marker generation device may have a light source associated with the positioning device. Integrating the imaging light marker generation device with the imaging device and / or the interventional light marker generation device and the positioning device can result in a reduction of space requirements.

  Preferably, the imaging light marker generation device and / or the interventional light marker generation device have a bridge structure for bridging the object, and a light source for generating an optical marker is attached to the bridge structure. The bridge structure preferentially has a portion above the object support of the position determination system, the light source being a surface of the object from above when the object is arranged on the object support To illuminate the part.

  In an embodiment, the imaging-time optical marker generation device and / or the intervention-time optical marker generation device are adapted such that different generated optical markers have different appearances. For example, different generated light markers can have different colors and / or different shapes. Furthermore, the imaging marker and / or the intervention marker may be adapted such that different generated markers are accompanied by a label for labeling each marker. The different appearances and / or labels may be used to guide the user in using the corresponding rays of the respective light marker generating device to generate the corresponding light marker at the position on the surface.

  The imaging-time optical marker generation device and / or the intervention-time optical marker generation device are preferentially adapted such that the different generated optical markers are light spots, for example no light rays.

  The position determination system further comprises, preferentially, a target support for supporting the target, the target support being adapted to align the target with six degrees of freedom. Since the object support is adapted to align the object with six degrees of freedom, the position determination system comprises a ray geometry used by the imaging light marker generation device and the intervention light marker generation device May be used in configurations where they are the same. That is, in this situation, the light marker generated by the interventional light marker generation device is also lighted by the light marker generation device at the time of imaging by aligning the object support in six degrees of freedom and thus the object accordingly. Markers may still be generated at locations on the surface of the object for which they were generated.

  The positioning system comprises a first marker for marking the position at which the light marker generated by the interventional light marker generation device is to be positioned during the calibration procedure, and when the positioning device determines the position of the catheter The system may further comprise a calibration phantom having a second marker for marking the position at which the catheter is to be positioned during the calibration procedure, the spatial relationship providing unit positioning the catheter at the second marker. And being adapted to determine the interventional spatial relationship based on the position of the catheter determined by the positioning device when the light marker is positioned at the first marker. This allows the spatial relationship donor unit to accurately determine the intervention spatial relationship. The interventional spatial relationship may be stored at the spatial relationship donor unit and may be read during the interventional procedure to determine the position of the catheter in the generated image.

In another aspect, there is provided an imaging system for imaging an object for use with the positioning system according to claim 1 to form a position determination system according to claim 2. The imaging system
An imaging device for generating an image of the object before the intervention procedure is performed at an imaging site;
An imaging-time optical marker generation device that generates an optical marker at a position on the surface of the object before the intervention procedure is performed at the imaging site.

In a further aspect of the present invention there is provided a positioning system for identifying the position of a catheter within a subject during an interventional procedure which is used in conjunction with the imaging system to form the positioning system. The positioning system is
A positioning device for determining the position of the catheter during the interventional procedure at the intervention site;
An interventional optical marker generation device for generating an optical marker at a position on the surface of the target at the time of imaging of the imaging system at the intervention site;
A spatial relationship donation unit providing an imaging spatial relationship between the imaging device of the imaging system and the imaging light marker generation device and an interventional spatial relationship between the positioning device and the interventional light marker generation device When,
And a position determining unit for determining the position of the catheter in the generated image based on the position of the catheter determined by the positioning device and the imaging spatial relationship and the intervention spatial relationship.

  In another aspect there is provided an optical marker generating device for use by the position determination system according to claim 2. The optical marker generating device comprises a bridge structure for bridging an object and a light source associated with the bridge structure, the light source being configured to generate an optical marker on a surface of the object. The optical marker generation device may be a separate device, ie not integrated with eg an imaging device or positioning device, such that a single optical marker generation device may be used with several devices. For example, a single light marker generation device may be used for another imaging device and / or another positioning device.

A further aspect of the present invention is a position determination method for determining the position of a catheter located within an object in an image of the object during an intervention procedure, comprising: A position determination method to be used is provided. The method is
Generating an image of the object by an imaging device before the intervention procedure is performed at an imaging site;
Generating an optical marker at a location on the surface of the object before the intervention procedure is performed by an imaging-time optical marker generation device at the imaging site;
Generating an optical marker at the location on the surface of the object by an interventional light marker generation device at the intervention site;
Providing an imaging spatial relationship between the imaging device and the imaging light marker generation device and an intervention spatial relationship between the positioning device and the intervention light marker generation device by means of a spatial relationship donor unit; ,
Determining the position of the catheter in the object during the interventional procedure by a positioning device at the intervention site;
Determining the position of the catheter within the generated image based on the position of the catheter determined by the positioning device and the imaging spatial relationship and the intervention spatial relationship by a position determining unit.

  In an embodiment, the method preferably further comprises the step of permanently marking the position on the surface of the object at the imaging site, the generation of an optical marker at the intervention site being the surface Generating the light marker at the marked position above. Here, the term "permanently" means that they are marked so that the position is still indicated, even if the light marker is no longer present. For example, a pen may be used to permanently mark the position. Of course, if desired, permanent marks can be removed. This means that the light marker generated by the light marker generation device at the time of imaging and the light marker generated by the light marker generation device at the intervention are actually generated at the same position on the surface of the object in a relatively simple manner You can be sure.

In another aspect of the invention, a calibration method is provided for calibrating the positioning system according to claim 1. The calibration method is
Providing a calibration phantom having first and second markers;
Generating an optical marker with the interventional optical marker generation device at a first marker of the calibration phantom;
Positioning the catheter at the second marker and determining the position of the catheter by the positioning device when the catheter is positioned at the second marker to provide a calibration position;
Determining an interventional spatial relationship between the positioning device and the interventional light marker generation device based on the calibration position.

In a further aspect of the invention, a positioning computer program is provided that identifies the position of a catheter in a subject during an interventional procedure. The positioning computer program is executed when the computer program is executed by a computer that controls the positioning device, the spatial relationship providing unit and the position determining unit of the positioning system according to claim 1.
Program code means for causing the positioning device to determine the position of the catheter during the interventional procedure;
An imaging spatial relationship between the imaging device of the imaging system used with the positioning system and the optical marker generating device at the time of imaging, in the spatial relationship providing unit, and between the positioning device and the intervention optical marker generating device of the positioning system Program code means for providing an interventional space relationship;
Program code for causing the position determination unit to determine the position of the catheter in an image generated by the imaging device based on the position of the catheter determined by the positioning device and the imaging spatial relationship and the intervention spatial relationship Have means and

  A positioning system according to claim 1, a position determination system according to claim 2, an imaging system, an optical marker generation device, a position determination method according to claim 10, a calibration method according to claim 12, and a positioning computer program according to claim 13 It should be understood that it has similar and / or the same preferred embodiments as defined in the section.

  It is to be understood that the preferred embodiments of the present invention can be any combination of the dependent claims or the embodiments described above with the respective independent claims.

  These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.

In the following figures:
An embodiment of a position determination system for determining the position of a catheter located in an object in an image of the object during an intervention procedure is schematically illustrated as an example. An embodiment of the imaging system of the position determination system is schematically illustrated as an example. An embodiment of a positioning system of a position determination system is schematically illustrated as an example. The distribution of the light markers in the human chest is represented as an example. The calibration phantom is shown schematically as an example. Fig. 6 shows a flowchart representing, by way of example, a method for determining the position of the catheter located in the object in the image of the object during the intervention procedure. Fig. 6 shows a flowchart representing, as an example, a calibration method for calibrating a position determination system. A further embodiment of the imaging system is schematically illustrated as an example.

  FIG. 1 schematically illustrates, by way of example, an embodiment of a position determination system for determining the position of a catheter located in an object in an image of the object during an interventional procedure. The position determination system 1 comprises an imaging device 14 for generating an image of the object 4 before an intervention procedure is performed at the imaging site, for example in an imaging room. In this embodiment, the imaging device 14 is an MR imaging device having an MR data acquisition unit 12, an MR control unit 13, an input unit 15 such as a keyboard, computer mouse, touch pad etc, and a display 16. is there. The MR data acquisition unit 12 is configured to receive MR data of the object 4 lying on the object support 5 such as a support table when the object support 5 with the object 4 is moved into the MR data acquisition unit 12. Configured to get Thus, the target support 5 is inserted into the MR data acquisition unit 12 to acquire MR data in the direction indicated in FIG. 1 by the double arrow 40 and after the MR data have been acquired It is movable out of the acquisition unit 12. The MR control unit 13 is configured to control the MR data acquisition unit 12 and optionally also the object support 5 and to reconstruct an MR image based on the acquired MR data. The reconstructed MR image may be shown on the display 16. The input unit 15 may be used, for example, to initiate a desired MR data acquisition and / or MR reconstruction procedure.

  The position determination system 1 further includes an imaging-time optical marker generation device 6 that generates an optical marker at a position on the surface of the object 4 at the imaging site. In this embodiment, the imaging light marker generation device 6 is configured to generate light spots as light markers. Thereby, the imaging light marker generation device 6 can also be regarded as an imaging light point generation device.

  The imaging point light generating device 6 has a bridge structure 7 with a horizontal part 9 and a vertical part 8 carrying a laser 10. A perspective view of an embodiment of the MR data acquisition unit 12, the imaging light spot generating device 6 and the target support 5 is schematically depicted in FIG. 2 as an example. As can be seen from this figure, the vertical parts 8 of the bridge structure 7 are located on both sides of the target support 5, the horizontal parts 9 being carried by the vertical parts 8 and thus above the target support 5 When the subject is lying on the subject support 5, it extends above the subject. In the example shown in FIG. 2, the laser 10 is arranged in the vertical part 8 and the horizontal part 9 in order to generate light spots on the surface of the object from different directions by using the light beam 11.

  Prior to imaging, the object 4 is represented in FIG. 1 such that a light spot can be generated on the surface of the object 4 at the imaging position, ie at the position relative to the object support 5 used during imaging. As such, it may be positioned in front of the MR data acquisition unit 12 in the bridge structure 7. The position of the light spot on the surface of the object 4 can be marked, for example, by using a color pen that does not lose color. The object support 5 and thus the object 4 is then moved into the MR data acquisition unit 12 while the object 4 is still in the imaging position. That is, the object 4 is considered not to be moved relative to the object support 5. The MR data is acquired by the MR data acquisition unit 12, and the MR control unit 13 reconstructs an MR image based on the acquired MR data. After the MR data are acquired, the object support 5 with the object 4 is moved out of the MR data acquisition unit 12. The MR imaging device 14 and the imaging point light generating device 6 may be considered to be part of the MR imaging system 2 that generates MR images.

  The position determination system 1 further comprises a positioning device for determining the position of the catheter 34 during the interventional procedure at the intervention site, such as the operating room where the interventional procedure is performed. In this embodiment, the catheter 34 comprises a hand grip 59. The catheter 34 is connected via a cable 33 to a control unit 37 having a radio frequency (RF) energy source 26. While performing the interventional procedure, the catheter 34 is used within the subject 4 lying on the subject support 24. The tip of the catheter 34 has one or more electrodes that apply RF energy within the subject 4 to perform, for example, an ablation procedure. The tip of the catheter 34 has an EM position sensor that interacts with the EM field generated by the EM field generator 25 located below the target support 24. The EM field generator 25 is connected to the control unit 37 via a cable 35. The control unit 37 controls an EM position sensor disposed at the tip of the EM field generator 25 and the catheter 34, and an EM signal generated by the EM position sensor at the tip of the EM field generator 25 and the catheter 34. The position control unit 27 determines the position of the tip of the catheter 34 in the object 4 based on the above. Thus, the positioning control unit 27 together with the EM field generator 25 and the EM position sensor at the tip of the catheter 34 form a positioning device which determines the position of the catheter during the interventional procedure at the intervention site.

  The position determination system 1 further comprises an interventional light point generation device 17 for generating an optical marker at a position on the surface of the object 4 for which the optical marker has been generated at the time of imaging at the intervention site. The interventional light point generating device 17 is also represented as schematically illustrated in FIG. 3 with the vertical portions 19 located on both sides of the target support 24 and the upper middle horizontal portion 20. It has a bridge structure 18 provided. Lasers 21 are disposed in the horizontal portion 20 and the vertical portion 19 to generate a laser beam 22. The laser beam 22 generates a light spot at a position on the surface of the object 4. In this embodiment, the geometry of the light beam 22 of the interventional light spot generating device 17 and the geometry of the light beam 11 of the imaging light spot generating device 6 are the same. The same position where the light spot generated by the light spot generation device 17 is also generated by the light spot generation device 6 at the time of imaging without changing the geometry of the light beam 22 of the light spot generation device 17 at the intervention time. The object support 24 has six degrees of freedom in order to align the object 4 as arranged at. Thus, if the position used by the imaging point light generating device 6 is marked on the surface of the object 4, then the target support 24 is also an object 4 for the light spots generated by the interventional light point generating device 17. Can be aligned so as to be located at the marked position on the surface of the.

  FIG. 4 shows schematically and by way of example a preferred position 32 on the object 4 on which the light spot is to be placed. As the arms are likely to be moved by the subject 4, the light spots 32 are preferentially distributed in the chest so that they do not cover the subject 4 's arms.

  The position determination system 1 provides an imaging spatial relationship between the MR imaging device 14 and the imaging light point generation device 6 and an intervention spatial relationship between the positioning devices 25, 27 and the interventional light point generation device 17 It further comprises a spatial relationship donating unit 28. The position determination system 1 determines a position determination unit 29 that determines the position of the catheter 34 in the generated MR image based on the position of the catheter 34 and the imaging space relationship and the intervention space relationship determined by the positioning devices 25 and 27. Furthermore, it has.

  In particular, since the optical marker generation device 6 generates an optical marker at a position on the surface of the object at the time of imaging, it is between the object coordinate system defined by the position on the surface of the object and the coordinate system of the optical marker generation device 6 at the time of imaging The spatial relationship of is known from the geometry of the rays used to generate the light marker. Furthermore, the spatial relationship providing unit 28 provides an imaging spatial relationship between the imaging device 14 and the imaging light marker generation device 6, ie, further, the coordinate system of the imaging device 14 and the imaging marker generation device 6. Because the spatial relationship between the coordinate system is known, the spatial relationship between the object coordinate system and the imaging coordinate system is also known. Furthermore, the interventional light marker generation device 17 generates a light marker at the position on the surface of the object which is equal to the position on the surface of the object generated by the light marker generation device 6 at the time of imaging. The geometry of the rays used by the interventional light marker generation device 17 to provide a spatial relationship between the object coordinate system and the interventional light marker generation device 17 coordinate system. Furthermore, in addition, the spatial relationship donating unit 28 is located between the positioning device 25, 27 and the interventional light marker generation device 17, ie, the positioning coordinate system of the positioning device 25, 27 and the coordinates of the interventional light marker generation device 17. The spatial relationship between the object coordinate system and the positioning coordinate system is also known, as it provides an interventional space relationship between the system. Thus, the spatial relationship between the imaging coordinate system and the object coordinate system, and the spatial relationship between the positioning coordinate system and the object coordinate system are known, so the catheter 34 determined by the positioning devices 25, 27 The position of may be accurately determined in the generated image. This determination of the position of the catheter 34 within the generated image does not necessarily require an x-ray projection image, thereby enabling a reduction of the radiation dose applied to the subject. In particular, it can result in interventional procedures that do not need to be applied to the subject with any x-rays.

  The imaging spatial relationship and the intervention spatial relationship may be predetermined in the corresponding calibration step, and the determined imaging spatial relationship and the intervention spatial relationship may be determined during the intervention procedure by the spatial relationship donating unit 28. And to be able to provide an interventional spatial relationship, it is stored in the spatial relationship providing unit 28.

  The positioning device, the spatial relationship providing unit and the position determining unit, together with the interventional light marker generation device, may be considered to be components of the positioning system 3 for locating the position of the catheter in the object during the intervention procedure. In this embodiment, the positioning system 3 is integrated with the system performing the interventional procedure, ie with the catheter and the RF energy source. A positioning system 3 equipped for performing an interventional procedure may be placed in a first room such as an operating room, in particular an EP lab, and an imaging system with an MR imaging device and an optical marker generation device at the time of imaging May be placed in other rooms, such as an imaging room. In this way, the position of the catheter within the subject may still be accurately indicated in the MR image during the intervention procedure, even though the generation of the MR image and the intervention procedure may be performed in another room. This allows the physician 36 to accurately guide the catheter 34 within the subject 4 based on the internal anatomy of the subject 4 shown in the generated image.

  A calibration phantom may be used to calibrate the interventional spatial relationship. The calibration phantom may have a cubic shape, as schematically illustrated in FIG. The calibration phantom 50 preferentially marks the position at which the light spot generated by the interventional light spot generating device 17 is to be positioned during the calibration procedure, and the positioning device at the tip of the catheter 34 When determining the position, it has at least three second markers 52 which mark the position at which the tip of the catheter 34 is to be positioned during the calibration procedure. More second markers increase the overall accuracy of the calibration. The calibration may be performed as a least squares fit, as known in the art. The first marker 51 is preferentially covered by a material that scatters the light more strongly than the remaining surface of the calibration phantom 50. This can simplify the process of orienting the phantom to align with the light. The second marker 52 is preferentially made as a depression in the calibration phantom 50 used to receive the catheter tip. One of the depressions is shown in FIG. 5 in an enlarged view. The indentation ensures that the tip is fixed in the very defined position. As most physiological catheters have a spherical tip shape, the recess therefore preferentially has a spherical shape such that a known position is achieved regardless of the catheter diameter. Special phantoms with appropriate indentations may be used for other tip shapes. The spatial relationship donor unit 28 positions the tip of the catheter 34 as determined by the positioning device when the tip of the catheter 34 is positioned at the second marker 52 and the light spot is positioned at the first marker 51. And may be configured to determine an interventional spatial relationship based on a known spatial relationship between the first and second markers 51,52. In FIG. 5, coordinate system 53 is the LPH (Left, Posterior, Head) coordinate system, and during the calibration procedure, calibration phantom 50 coordinates as shown in FIG. It may be aligned with the system 53. It should be noted that during calibration, calibration phantom 50 may be aligned in other manners.

  In the following, an embodiment of a position determination method for determining the position of a catheter located in an object in an image of the object during an interventional procedure is described by way of example with reference to the flow chart shown in FIG. It is stated to be

  In step 201, the light spot 32 is generated by the imaging point light spot generation device 6 at a position on the surface of the object 4 at an imaging site such as an imaging room. At step 202, the position on the surface of the object 4 at which the light spot 32 is generated at the imaging site is marked, for example by using a color pen that does not lose color. At step 203, an MR image of the subject 4 is generated by using the MR imaging device 14 at the imaging site. Steps 201-203 may be performed in other orders. For example, step 203 may be performed before steps 201 and 202. After the MR image is generated, the subject 4 may be moved to an intervention site such as an EP room or EP lab where the intervention procedure may be performed.

  At step 204, the object 4 is placed on the object support 24 in an interventional position, ie in a position to be used during an interventional procedure. This interventional position is such that the intervention point light point generating device 17 can generate a light point 32 at the marked position on the surface of the object 4. In particular, the target support 24 is moved so that the light spot generated by the laser of the light spot generating device 17 at the intervention coincides with the position marked in step 202. At step 205, the imaging spatial relationship between the MR imaging device 14 and the imaging point light generating device 6 and the intervention spatial relationship between the positioning devices 25, 27 and the intervention point light point generating device 17 are spatial relationship donations. Provided by unit 28. At step 206, when the subject 4 is in the interventional position, the position of the catheter 34 in the subject 4 during the interventional position is determined by the positioning devices 25,27. Then, in step 207, the position of the catheter 34 in the generated image is determined by the position determination unit 29 based on the position of the catheter 34 determined by the positioning device 25, 27 and the imaging spatial relationship and the intervention spatial relationship. Ru. The determined position is indicated on the display 31 in the MR image. At step 208, it is checked if the cancellation criteria are met. The discontinuation criterion is that the interventional procedure has been completed, or that the physician has entered via the input unit 30 that the determination of the position of the catheter 34 in the generated MR image should be halted. You may If the abort criteria are not met, the method continues with step 206. Otherwise, the method ends at step 209. The position of the catheter, in particular of the tip of the catheter, may thus be continuously determined and shown in the MR image while the catheter is moved through the object until the stopping criteria are fulfilled.

  In the following, an embodiment of a calibration method for calibrating the position determination system is described as an example with reference to the flow chart shown in FIG.

  At step 301, a calibration phantom is provided having first and second markers. For example, a calibration phantom may be disposed on the target support 24. At step 302, a light spot is generated by the interventional light spot generation device 17 at the first marker of the calibration phantom. At step 303, the tip of the catheter 34 is positioned at the second marker and the position of the tip of the catheter 34 is determined by the positioning devices 25, 27 when the tip of the catheter 34 is positioned at the second marker, Thereby, a calibration position is generated. At step 304, the interventional spatial relationship between the positioning devices 25, 27 and the interventional light point generation device 17 is determined based on the calibration position and the known spatial relationship between the first and second markers. Ru. Intervention spatial relationships may be stored at spatial relationship donation unit 28 to enable spatial relationship donation unit 28 to provide intervention spatial relationships during an interventional procedure.

  In this embodiment, the calibration geometry provided by the interventional light point generation device 17 is fixed. Thus, at step 302, a light spot is generated at the first marker of the calibration phantom by placing the calibration phantom accordingly. That is, the calibration phantom is aligned such that the first marker coincides with the light spot generated by the light spot generation device at the time of intervention.

  Conventional catheter ablation procedures are usually guided by x-ray fluoroscopy, often supplemented by an EMT system. Some work steps are often complemented by intracardiac echo (ICE; IntraCardiac Echo) and transesophageal echo (TEE; TransEsophagal Echo) imaging. In addition, intracardiac electrograms (IE; Intracardiac Electrograms) are acquired to provide position information based on known cardiac excitation patterns.

  The catheter ablation procedure is described in the article "Nonfluorescent Catheter Ablation of Cardiac Arrhythmias in Adults: Feasibility, Safety, and Efficacy" by M. Razmina et al. ing. This procedure uses only IE, EMT and ICE for catheter guidance and does not use x-ray fluoroscopy. In this non-fluoroscopic (NF) procedure, the catheter needs to move around the vasculature and within the ventricle to "make" the roadmap for guidance during the procedure. In synchronization with this, manual segmentation needs to be performed by the additional operator during the intervention. However, there is no way to "look ahead". That is, there is no anatomical information from the position where the catheter is going to next but not yet. For example, there is no available information on pulmonary vein deformities in patients with atrial fibrillation (AF) that affect ablation strategies. The position determination system described above with reference to FIGS. 1 to 4 thus improves the guidance during the interventional procedure, in particular preoperative imaging to provide a three-dimensional roadmap for catheter guidance. I will provide a.

  The position determination system is preferentially a preoperative three-dimensional imaging modality such as the MR imaging modality described above, or a modality such as CT, rotation, x-ray, positron emission computerized tomography (PET), etc. Other three-dimensional imaging modalities. Such imaging modalities are equipped with a laser bridge, i.e. an imaging point generating device, to mark specific points on the patient during preoperative imaging. The positioning system is preferentially equipped with an EMT system, ie a positioning device, and a second identical laser bridge, ie an interventional light point generating device, to allow alignment of the patient relative to that laser bridge In addition, it has an NF EP lab. In addition, a method of registering a preoperative data set with the EMT system and displaying at least a portion of the data set with a catheter position derived from the EMT is preferentially provided.

  The preoperative imaging modality may be equipped with the laser bridge described above with reference to FIG. The laser bridge does not generate a line, and the laser bridge may mark N points on the patient's chest by using N individual laser pointers in a fixed geometry. The points are preferentially distributed in the chest so that they do not cover the patient's arm. This is particularly preferred when the interventional procedure is to be applied to the heart, as the arms are in fixed geometrical relationship with the patient's heart. The color of the lasers may be different, or labels may be displayed beside the point to distinguish them. Not all rays / points provided by the system may be used for a particular patient. The EMT system may be equipped with a laser bridge having exactly the same ray geometry as used prior to surgery. The field generators of the EMT system are preferentially in a fixed known geometrical relationship with the laser bridge. Usually, the table with the patient can be moved with six degrees of freedom relative to the laser bridge.

  The field generator of the EMT system defines the coordinate system in which the catheter is tracked. Thus, it is preferentially at a fixed position relative to the laser bridge defining the preoperative coordinate system. The field generator of the EMT system is preferentially aligned with the laser bridge only once during setup of the system, but may be reconfirmed for safety reasons. The calibration may be performed using a special phantom, ie the calibration phantom described above. The phantom has a marker that needs to be aligned with the laser bridge, ie a first marker. The phantom is a marked position where the coordinates are known relative to the first coordinates, and thus to the laser bridge system when the laser bridge is aligned with the first marker, ie the second marker Furthermore, it has. During the calibration process, their marked positions are approached by the catheter. At their position, the field generator detects the position of the catheter in its own coordinate system. These coincidence points are used to calculate the coordinate transformation from the laser bridge system to the EMT system, ie the spatial relationship between the interventional light point generating device and the positioning device that can be stored in the spatial relationship providing unit You may

  In an embodiment, during the preoperative imaging procedure, the patient is prepared in front of the bore of the MR bore or other imaging modality such as a CT bore for preoperative scanning. The MR or CT light visor may be used to accurately position the patient for scanning at the isocenter of the system. The laser points from the bridge are then projected onto the patient, and those points are marked and labeled on the patient's skin using a color pen that does not lose color. Only those points are used and do not project onto the arm. The patient is placed in the bore and an initial preoperative scan is performed. The patient is then returned to the front of the bore to confirm positioning. If the patient is moved, he / she is repositioned to align the laser point with the mark on the skin and the scan is repeated. This scheme can avoid that more than one scan should be redone. The preoperative image data is transferred to the EMT system via, for example, DICOM (Digital Imaging and Communications in Medicine). Segmentation or further information of intravascular surfaces may be derived from these data. The patient is then aligned under the laser bridge system in the EP lab. A table with six degrees of freedom is used to align the patient so that the laser point is aligned with the marker on the patient's skin. The patient's position may be reconfirmed repeatedly during the procedure. During the interventional procedure (in this embodiment a catheter procedure), the catheter is tracked using an EMT system, ie using a positioning device. Anatomical expressions derived from preoperative data may be rendered with the model of the catheter to improve guidance.

  The above-described systems and methods are preferentially used to provide an endovascular surface with an EMT catheter location to improve catheter guidance. Still further information may be extracted from the preoperative image and shown to the user along with the EMT catheter position, such as a wall thickness map that may be calculated preoperatively from the preoperative image. Furthermore, in myocardial biopsy, biopsy target locations may be pre-operatively imaged by MR with sufficient contrast, segmented, numbered and provided as a work schedule during the interventional procedure . Hazardous structures to be avoided by the catheter may be pre-marked and indicated during the interventional procedure. The position determination system and method may be used in cardiac interventions, but may also be used in non-cardiac interventions such as interventional procedures that treat major blood vessels in neurovascular space.

  In the embodiment described above with reference to FIGS. 1-3, the imaging point and intervention point light point generation devices have particular structures, but in other embodiments they can be configured in other ways . For example, they may have bridge structures configured differently, or they may not have any bridge structure. For example, the light source may be incorporated in the imaging device and / or positioning system to provide an imaging point light point generation device and / or an intervention point light point generation device, respectively. In particular, as represented schematically in FIG. 8 as schematically illustrated, the imaging system 102 can comprise an MR data acquisition unit 112 with a target support 105, wherein the MR data acquisition unit 112 comprises A laser is incorporated such that the laser beam 111 emits from the MR data acquisition unit 112. In a further embodiment, the imaging device may be equipped with a light source generating a light spot on the surface of the object, and in addition, a bridge structure with a further light source generates a light spot on the surface of the object May be used for

  In the above embodiments, the imaging-time optical marker generation device and the intervention-time optical marker generation device use the same fixed configuration geometry to generate optical markers at the same location on the surface of the subject, but in other embodiments, The optical marker generation device upon imaging and / or the optical marker generation device upon intervention may use different configuration geometries that may be fixed or changeable. For example, the imaging marker and / or the intervention marker may be configured to change the beam geometry such that the marker is generated at the same location at the imaging site and at the intervention site. The position determination unit may be configured to determine the position of the catheter in the generated image based on the position of the catheter determined by the positioning device, the imaging spatial relationship and the intervention spatial relationship, and the ray geometry.

  In the above embodiments, the positioning device is an EMT device, but in other embodiments other positioning devices may be used as well as OSS positioning devices.

  Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims.

  In the claims, the word "comprising" does not exclude other elements or steps, and the singular (the use of the article a or an) does not exclude a plurality.

  A single unit or device may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures can not be used to advantage.

  The procedures performed by one or more units or devices, such as providing spatial relationships and determining the position of the catheter in the generated image, may be performed by any number of units or devices. The control of the positioning device, the spatial relationship providing unit and the position determining unit according to the steps 206 to 209 of these procedures and / or position determining methods may be implemented as program code means of a computer program and / or as dedicated hardware.

  The computer program may be stored / distributed on a suitable medium, such as an optical storage medium or solid state medium, supplied with or as part of other hardware, but in other forms as well, for example the Internet or other It may also be distributed via a wired or wireless telecommunication system.

  Any reference signs in the claims should not be construed as limiting the scope.

  At the imaging site, before the intervention procedure is performed, the imaging device generates an image of the object, and the imaging light marker generation device generates an optical marker at a position on the surface of the object at the time of imaging. At the intervention site, during the intervention procedure, the light marker generation device at the time of intervention generates a light marker at the position on the surface of the object, and the positioning device determines the position of the catheter. The position determination unit is then based on the position of the catheter determined by the positioning device and the provided spatial relationship between the device used to generate the image and the light marker and the device for locating the catheter. , Determine the position of the catheter in the preoperative image. This makes it possible to indicate the position of the catheter in the preoperative image, without necessarily using x-rays.

Claims (13)

A positioning system for use with an imaging system to identify the position of a catheter within an object during an interventional procedure, wherein the imaging system is an imaging site before the interventional procedure is performed. A positioning system comprising: an imaging device for generating an image; and an imaging-time optical marker generation device for generating an optical marker at a position on the surface of the object before the intervention procedure is performed at the imaging site.
A positioning device for determining the position of the catheter during the interventional procedure at the intervention site;
An interventional optical marker generation device for generating an optical marker at a position on the surface of the target at the time of imaging of the imaging system at the intervention site;
A spatial relationship donation unit providing an imaging spatial relationship between the imaging device of the imaging system and the imaging light marker generation device and an interventional spatial relationship between the positioning device and the interventional light marker generation device When,
A positioning unit that determines the position of the catheter in the generated image based on the position of the catheter determined by the positioning device and the imaging spatial relationship and the intervention spatial relationship. A position determination system for determining the position of a catheter located within an object in an image of the object during an interventional procedure, comprising:
An imaging device for generating an image of the object before the interventional procedure is performed at the imaging site, and a position on the surface of the object before the interventional procedure is performed at the imaging site. An imaging system having an imaging-time optical marker generation device for generating an optical marker;
A positioning system, comprising: a positioning system for locating the position of a catheter within the subject during the interventional procedure as defined in claim 1. The imaging light marker generation device comprises a light source emitting a light beam according to a first beam geometry to generate a light marker,
The interventional light marker generation device comprises a light source emitting a ray according to a second ray geometry to generate a light marker,
The first ray geometry and the second ray geometry are the same,
The position determination system according to claim 2. The imaging light marker generation device and the imaging device are integrated,
The imaging-time light marker generation device has a light source associated with the imaging device,
The position determination system according to claim 2. The imaging-time optical marker generation device and / or the intervention-time optical marker generation device have a bridge structure that bridges the object,
A light source generating an optical marker is associated with the bridge structure
The position determination system according to claim 2. The imaging-time optical marker generation device and / or the intervention-time optical marker generation device are adapted such that different generated optical markers have different appearances.
The position determination system according to claim 2. The imaging-time optical marker generation device and / or the intervention-time optical marker generation device are adapted such that different generated optical markers are light spots.
The position determination system according to claim 2. The position determination system further comprises an object support for supporting the object;
The object support is adapted to align the object with six degrees of freedom,
The position determination system according to claim 2. The positioning system comprises a first marker for marking the position at which the light marker generated by the interventional light marker generation device is to be positioned during the calibration procedure, and when the positioning device determines the position of the catheter Further comprising a calibration phantom having a second marker that marks the position at which the catheter is to be positioned during the calibration procedure;
The spatial relationship donor unit is at the position of the catheter determined by the positioning device when the catheter is positioned at the second marker and the light marker is positioned at the first marker. Adapted to determine said intervention space relationship based on
The position determination system according to claim 2. An imaging device for generating an image of an object before an intervention procedure is performed at an imaging site, and an optical marker at a position on the surface of the object before the intervention procedure is performed at the imaging site an imaging system having an imaging time of the optical marker generation device for generating said and a positioning system for identifying the position of the catheter within said subject during interventional procedures, the subject of the image during the interventional procedure A method of operating a position determination system to determine the position of a catheter located within the object,
A step wherein the imaging device of the imaging system, in the imaging field, before the intervention procedure is performed, to generate an image before Symbol subject,
A step wherein the image capture optical marker generating device of the imaging system, the Te imaging scene smell, before the intervention procedure is performed, to generate a light marker at a location on the surface of the object,
Generating an optical marker at the location on the surface of the object at the intervention site, at the intervention site, the interventional optical marker generation device of the positioning system ;
A step positioning device of the positioning system, to determine at the intervention site, the position of the catheter in said object between said intervention procedure,
Spatial relationships donor unit of the positioning system, and the imaging spatial relationship between the imaging device and the imaging time of the optical marker generation device and intervention spatial relationship between the positioning device and the intervention time of the optical marker generating device Providing steps,
A step of position determination unit of the positioning system, based on the position and the imaging spatial relationship and the intervention spatial relationship of the catheter as determined by the positioning device, to determine the position of the catheter within said generated image A method of operating said position determination system . Generation of light markers on the previous SL intervention site includes generating the optical markers in permanently marked the positions on the surface of the object in the imaging field,
A method of operating the position determination system according to claim 10. A step of calibration phantom of the position determination system, the intervention time of the light marker generated by the light marker generation device is marked by the first marker position to be positioned between the calibration procedure,
A step wherein the calibration phantom of the position determination system, which thus marks the position to be positioned at a second marker between the catheter the calibration procedure when the positioning device determines the position of the catheter,
The spatial relationship donor unit of the position determination system, the catheter has the second and the light marker is positioned in the marker is positioned on the first marker Rutoki, determined by the positioning device based on position emissions of the catheter, and a step of determining said intervention spatial relationships, operating method of the position determination system according to claim 10. When executed by computer, in the computer, to execute the method of operation according to any one of claims 10 to 12, for controlling the position determination system
Computer program.

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